PIR Activated Sound Effects

black2002ls

First off, this is my first post to the forums. My background is a bit dated. I had a lot of advanced electronics courses while getting my Physics degree. That was about 5 years ago, so I'm a little rusty. Here is what I am trying to do:

Create a motion activated sound effect.

Parts:

Radioshack 20 second recording module #276-1323
Parallax PIR motion sensor #555-28027 Rev B

Here is what I'm having trouble with. The play back on the recording device triggers by closing the ground circuit. Can I use the output pin on the PIR to trigger a low voltage to the play back circuit on the recorder?

SRLM

Edit: I reread the PM, and it looks like it was targeted. Thanks!

But, the problem is interesting enough that I got hooked.

---

There are a few issues that I see here:
1. IIRC, the PIR has a pulse output during motion. So, it sends a pulse every second (guess). Will this cause the module to keep restarting the playback?
2. How is the Radioshack module record the sound clip? IIRC, it's by holding down the button. So, the PIR will have to send just one pulse to the device, not a continuous signal (low or high).
3. How much current does the Radioshack module draw through the button? If it's small (~<5mA) you can probably just hook up the PIR in place of the button. Otherwise, you need a transistor to provide a higher current. You'd also need a transistor if the output of the PIR is opposite to what you need.

If it were me, I'd probably try just hooking up the PIR in place of the button. It's unlikely to damage anything besides the wires, and it might just work. Do so at your own risk (expense), though.

---

SRLM

You could try using a relay as well. The PIR would be hooked up to the relay control, and the contacts would take the place of the button. This might work:
http://www.radioshack.com/product/index.jsp?productId=2062478

This one would be better:
http://www.radioshack.com/product/index.jsp?productId=12477120

Look on the relay, and you should see something about NO and NC. That would allow you to reverse the logical on state (in case the no-motion case is triggering the module).

black2002ls

Thanks for the input. I popped the fuse in my multi meter last night while not paying attention to what I was doing. I will be headed to radio shack this morning for some more supplies. I'll pick up one of those relays as well as some transistors and other goodies. My electronics toy box is non existent

Also, I'm trying to accomplish this without an arduino

black2002ls

I picked up the first relay you linked, the second one was not available. Assuming I have this connected properly, I am only using the trio of pins. I have the ground and positive terminals across from each other and the signal from the PIR at the tip of the triangle. I am having a constant closed situation, where it trips the circuit no matter what. I don't see a way to reverse this with the relay I have. Do I need a different relay?

black2002ls

Alright! I got this to work. I had the coil in the resistor wired the wrong way. I now have the ground for the play back circuit wired to the NO and Common terminals on the relay. The Coil is wired with the output from the PIR on one terminal, and the ground from the PIR on the other terminal, and it works flawlessly. Now, can I secure these boards inside of a project box with hot glue?

SRLM

Hot glue will work fine. You can also use double sided tape.